const arrayMap = <T, U>(
  array: T[],
  callback: (item: T, index: number, arr: ReadonlyArray<T>) => U
): U[] => {
  let i = -1
  const len = array.length
  let resArray = []
  while (++i < len) {
    resArray.push(callback(array[i], i, array))
  }
  return resArray
}

// export = arrayMap

const a = 1
const b = 2
const c = 3
export = {
  a,
  b,
  c,
  arrayMap,
}
